By: Ramesh Kaphle
ENVIRONMENTAL problems are at top priority since last few decades as these are directly vulnerable to human beings, animals, crops and surrounding environment as well. These issues are so vital to discuss and are not ignorable at any cost. Hospitals are the places of health care and if waste will be not disposed off properly then most of the stakeholders may get infected especially employees working in the hospital, patients and surrounding communities also which could cause more troubles than the original ones. Infectious waste can be source of diseases like Hepatitis, AIDS, Typhoid and Boils etc.
Most of the hospitals are places to generate pathological, sharp and non-sharp infectious wastes; among those hospitals generate chemical wastes and radiological waste. Before entering into detail of solid/hazardous waste management of hospital, it is necessary to know about the different kind of medical wastes; the hospital waste has classified into different categories.
Biomedical waste needs spatial care and concern to dispose it properly because it cannot mix with household or other kinds of wastes. A separate and fully equipped technology is required to deal hazardous waste; inappropriate technology may lead to different unwanted direct problems not only to humans but environments as well. The objectives of this case study were to identify the current situations of waste management in hospitals in Kathmandu and to suggest appropriate technology(s) on sustainable basis and cost effective as well to manage the waste efficiently and appropriately. Currently, hospitals in Kathmandu have no solid/hazardous waste solution on long run and sustainable basis; hospital waste is mixed with bio degradable and recyclable waste without any deliberation to find out its proper solution.
The term paper is based on secondary information different articles and journals along with different textbooks and websites, newspaper were reviewed several times to finalize this term paper.
III. OVERVIEW OF EXISTING SITUATION
Current scenario of the hospital waste management is quite simple and straight in terms of management. According to annual health report published by Department of Health Services 2000/2001 there are 74 Hospitals, 172 Primary Health Care Units, 710 Health Posts and 3132 Sub-health Post in Nepal. In total 4088 health care institutions (HCIs) produce a large amount of health care waste (HCW) in across the country, and is invariably mixed with other non-infectious waste The amount of hospital waste generated in Nepal is approximately 1.7kg/person/day. Average incinarable waste generation rate is 396.77gm/day/bed, Infectious waste generation rate 0.48kg/person/day. All together, these HCI have the capacity of 3905 hospital bed. These HCIs produce 1300kg of infectious waste per day in the Kathmandu valley.
More than 90% of healthcare institutions do not practice safe waste handling, storage and disposal methods and most healthcare institutions rely on municipal services for their ultimate disposal. In Kathmandu Valley, Tribhuvan University Teaching Hospital and Patan Hospital have incinerators to treat their wastes. According to the study conducted by Save the Environment Foundation (SEF), hospitals collect all medical wastes including pathological wastes, syringes, bandages and others in a normal bin and dump into the municipal containers. Personnel who handle those wastes do not use even gloves while dumping the material Since 1996, the problem of biomedical waste has been considered as a cross cutting issue by the Government of Nepal, resulting in formulation of Medical Waste Management and Handling Rules. There is no proper management system for disposal of biomedical waste in most of HCIs. The segregation of waste at source (wards, O.T, and lab) is far from satisfactory and it was also found that collection of non-infectious and hazardous waste done in open hand–driven trolley. Some HCIs were using plastic buckets of assorted variety at ward and department level for waste collection, however most of them were in broken condition and replacement was not provided.
Bir Hospital Set an Example
Bir Hospital, country’s oldest hospital recycles 80% of its total waste. With the recycled waste, a garden has been constructed and the management makes NRS 30,000 a month by selling fertilizer. It is now a mercury free zone. The hospital produces more than 320 kg of infectious waste daily.
In Medical waste management by managing highly infected waste piled up inside hospital premises, the Bir administration in cooperation with Health Care Foundation-Nepal (HECAF) had launched the medical waste management programme on July 20, 2010. The start of waste management is spreading a positive message and helping maintain cleanliness and hygiene of the hospital at the same time, say officials of the hospital. In all 26 indoor wards, where patients are shifted for advance medical treatment and observation, have separate buckets for the segregation of waste. This helps to reduce menace of cockroaches and rats.
Hospital waste management practice in Kathmandu wasn’t found satisfactory beside there are good hospital waste management practice. Bir Hospital set a good example of hospital waste management practice. The segregation, collection, transportation and disposal practice of the hospital waste practice was found unsatisfactory.
IV. SELECTION OF APPROPRIATE TECHNOLOGY
Wastes - both solid and liquid are generated from various areas of a typical Hospital. The areas from where the wastes are generated would vary depending upon the type of facilities in the hospital. From a typical hospital the wastes generated would be as follows: S No| Area| Specific Areas Like| Solid Separable atSource Waste| Liquid / Semi Solid Waste| 1.| GeneralHospital Area| Non Patient Area -Residence, Administration etc.| Normal CommunalGarbage / Refuse| Normal Liquid Waste Water| 2.| Hospital Patient Area| Patient Areas –OPD, Wards etc.| Solid wastes will contain bandage ,and other disposal consumable refuse which could be infected| From the Toilet Areas of the Wards / OPD – the liquid waste in all likely hood could carry pathogenic infectious contaminants| 3.| HospitalCritical Areas| Comprising of OT,ICCU, Labor Room Emergency Areas| Solid wastes will contain bandages, and otherdisposal consumable inaddition to waste organictissues, placenta refusewhich would be infected| From the Toilet and Wash Area of the OT ICCU etc. - the liquid waste in all likely hood could carry pathogenic infectiouscontaminants in addition to blood , some organic tissues etc.| 4.| Service Areas| Areas like Linensupply for thewards , OT SterileSupply , catheterLab etc.| Normally not much solidwaste would be generated from these areas - except of discarded linen - whichcannot be reused and must be disposed| Substantial waste water would be generated from this area in the washing and reprocessing of linen and other reusable consumable in a hospital. The waste water generated will be contaminated - with the contamination coming from the contaminated linen inaddition to the detergents, dirt from the linen reprocessing| 5.1| LaboratoryServices| NormalPathologicalLaboratory| Solid wastes wouldcomprise tissue cultureand experimental deadanimals carcasses etc.and disposablelaboratory consumable| Washings of reusableglassware comprising ofdisposable pathologicalsamples comprising oforganic in addition to spentChemicals. This wastewater will be contaminated| 5.2| Services nuclearLaboratory /noninvasiveInvestigationTechniques| Nuclear Laboratoryand Non InvasiveInvestigation Areaemploying NuclearIsotopes| Nuclear Solid Wastescomprising of spentIsotopes and Isotopecontainers| Spent liquid Isotopes -normally not much liquidwastes| 5.3| Services-Non InvasiveTechniquesDept.X| X Ray and otherNon InvasiveTechniques likeCAT / NMR /Ultrasound ,Endoscopy andother non-invasivetechniques| Spent film wrapping ,exposed film etc.| Film developing wastebaths containing spentdeveloper containingmetals like silver etc. andother chemicals| 6.| CateringServices| Central Kitchen /Pantry for foodpreparation &serving| Solid waste comprising of• Food pre & preparation wastes• Waste food after serving - this could be contaminated with pathogens| Liquid wastes generated incatering comprising of• Food pre & preparation wastes Spent cooking medium etc.• Washings of served food utensils etc. - likely to becontaminated with pathogens|
The above table lists the likely wastes both solid & liquid generated from a typical hospital complex. The purpose of this note as mentioned is to identify the sources of wastes and to suggest the method of collection and disposal of the wastes.
1. Solid Wastes:
The Solid wastes should be segregated at the source and collected in separate containers. a. The non-contaminated solid wastes can be disposed along with the communal garbage refuse on sanitary landfill b. The contaminated wastes collected separately will have to be incinerated on the on-site incinerator c. Plastic Wastes to be collected separately and disposed for recycle or incinerated if contaminated. d. Glass wastes to be collected separately and sent for recycle.
2. Liquid Waste Waters
Liquid wastes need to be collected in a liquid waste collection system and then treated in a waste water treatment plant. The wastes will be / should be segregated depending on the pollutant. - I.e. weather it is Innorganic or Organic in nature, chemical with heavy metals or nuclear with isotopes. There is no need to segregate the organic liquid wastes contaminated with pathogens or not as the downstream waste water treatment system functions and is designed on the basis of pollutant and not weather the waste water has pathogens. The treatment system in case of pathogenic contaminants has to have further additional steps to “Hygenise” the treated waste water after removal of the primary pollutant - i.e. organic , chemical etc. Based on the waste water sources listed above the following streams need to be segregated.
a) X - Ray Waste Waters
X ray waste water containing heavy metals like silver and spent chemicals. This waste need to be treated separately for removal and recovery of Heavy metals. The treatment steps being –
iii. Reaction to precipitate Heavy metals as sludge
iv. Phase Separation of precipitate and dewatering of sludge for recovery of metals. The liquid waste can be then mixed with the other organic waste waters.
b) Radio Active Containing Waste Waters
Radio Active waste waters - these need to be separated - contained and disposed is a designated radioactive waste disposal area after containment. The ultimate disposal method will depend upon the nuclear / radioactive contaminant.
c) Organic Pollutant Containing Waste Water
The balance waste water will be basically containing organic wastes of human origin and as this waste is coming from a hospital it will have a high possibility of pathogenic contamination. Therefore this waste needs to be handled with care and has to have special treatment prior to disposal. The recommended treatment would basically comprise of the following
i. Waste Collection in closed sewer system in the complex. ii. Collected waste Sump / Pit
iii. Screening of waste in an enclosed fine ( opening size less than or equal to 5 mm ) Plastic or Stainless Steel mechanical bar screen The screenings need to be dewatered , compacted and then collected in compacted form in plastic bags and disposed by incineration. The screenings should not be disposed as land fill and in drained condition as the screenings will be very likely to contain pathogenic materials. iv. After screening the waste water will go to an aerated fat / sand trap with a facility of removal of scum (floating oil). v. Aerobic Bio Reactor - Suspended Growth with diffused aeration system and aerated in a covered tank and the outlet air being vented out first through filters and then through especially designed aerobic Bio filters to remove pathogens and any odor. All units will be covered and the air vented through the fabric filters followed by bio filters. vi. The organic pollutants both dissolved and fine suspended / colloidal will be converted by the aerobic microorganisms which are generally nonpathogenic to more microorganisms - using the organic matter as a source of food and oxygen from the air being bubbled through fine bubble membrane diffusers. vii. The Bio Reactor will be followed by a settling tank where the bio-mass / micro organisms will settle. A portion of this settled bio mass will be recycled to the aerated aerobic bio reactor for proper F/ M. Some excess bio mass (Sludge) will have to be wasted. There is a strong possibility of this sludge being contaminated, therefore it must be dewatered and Stabilized as well as hygenised for safe disposal. The possible alternatives for safe disposal of the excess sludge are:
1. Mechanical contained dewatering and then disposal by incineration in the Hospital Solid waste Incinerator. 2. Stabilization & Hygenisation after dewatering by mixing with powdered lime - which on mixing with dewatered produces “heat” which will ensure a positive kill of pathogenic organisms, and then disposal in land fill. 3. Aerobic Thermophilic Auto-thermal Digestion (ATAD) process by which the sludge will be hygenised & stabilized (System will operate at 60 deg. C plus ensuring positive kill of pathogens (EPA - of USA has published data on these type of reactors). 4. Pasteurizing - Flash heating of the excess sludge prior to dewatering to 75 - 80 deg. C to ensure a positive pathogen kill.
viii. The overflow treated waste water from the settling tank could also have pathogens so it must be Hygenised prior to disposal. The routes of hygenisation are
1. Ultra-Violet (UV) radiation.
3. Chlorination - Recommended is chlorinating as it will be fool proof and have a lower cost.
ix. The “Hygenised “liquid waste can after this step can be disposed in to the receiving water body safely of if desired be used after tertiary treatment as horticulture water. The tertiary treatment would essentially comprise of Sand Filtration followed by activated carbon filtration.
Environment and health are two main concerns of each hospital required to be in flow exactly so that each common may not be affected by these problems. Waste itself is a big host to damage environment and health; especially patients of hospitals are sensitive being there. The study has tried to find the best solution for hospital waste and concluded that sanitary landfill and incineration are two best appropriate technologies to adapt. Furthermore, incinerations is declared best being cost effective, less pollutant and most feasible as compared to sanitary landfill which is alone not a sustainable solution of waste management in hospital. In fact, the emissions from the incinerator lead to major health and environmental problems to the surrounding area. These can be mitigated by adapting simple technology. Precipitators are available to catch the dust particles from smoke and gas by adding this tool to the system; it is possible to reduce the dust problem efficiently on sustainable basis. Most of the polluted gases will disappear if the temperature set at more than 1200 degree Celsius. It is necessary to regulate system to the temperature more than 1200 degree Celsius to incinerate the infectious hospital wastes.
The above concept of Total Hospital Waste Management System including Waste Water Treatment System described above ensure that all wastes from the health care institutions will be discharged/disposed in a form that will not cause any Environmental Damage or Risk to Human Life.
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